The use of so-called cloud computing systems is becoming popular these days. In a cloud computing system, a data process request is transmitted from a client such as a portable terminal to a server, data processing is performed at the server, the result of the data processing is returned to the client, and the client obtains the result of the data processing.
An example of the use of such a cloud system is a game played on a portable gaming machine. The portable gaming machine (a client) being operated by a user communicates with a server, and image data such as a game development image and audio data are provided to the client with the use of a highly-sophisticated data processing function of the server.
In such a cloud-type gaming system, user action information is transmitted from the client to the server. In accordance with the action information received from the client, the server develops the game, generates updated images and audio data, and transmits those images and data to the client. The client reproduces the updated images and sound received from the server. By conducting such a process, even a client that does not have a sophisticated processor or the like can obtain results of data processing performed with the use of a highly-sophisticated data processing function of the server.
However, in the data being transferred between the server and the client, delays or jitter (fluctuations) occurs due to a network condition. Normally, image and audio data is transmitted as encoded data, and it is necessary for the client to sequentially decode and output the received data.
When delays or jitter (fluctuations) occurs due to a network condition, the series of processes such as packet reception, decoding, and display on the client side are disturbed, and a discontinuous image or intermittent sound might be generated.
As a technique to solve problems such as intermittent sound due to delays of communication data or the like, a process of changing the audio reproduction speed in accordance with packet delays is disclosed in U.S. Pat. No. 8,560,331 B1.